[turbofan] Add support for transitioning stores to double fields.

src/compiler/access-builder.cc

Index: src/compiler/access-builder.cc
diff --git a/src/compiler/access-builder.cc b/src/compiler/access-builder.cc
index 791453c3dfc005cf2212f564614473097c082885..0492b801b30f22dab8f8d4e920cc53f47ecb4733 100644
--- a/src/compiler/access-builder.cc
+++ b/src/compiler/access-builder.cc
@@ -23,6 +23,15 @@ FieldAccess AccessBuilder::ForMap() {
 
 
 // static
+FieldAccess AccessBuilder::ForHeapNumberValue() {
+  FieldAccess access = {kTaggedBase, HeapNumber::kValueOffset,
+                        MaybeHandle<Name>(), TypeCache().Get().kFloat64,
+                        kMachFloat64};
+  return access;
+}
+
+
+// static
 FieldAccess AccessBuilder::ForJSObjectProperties() {
   FieldAccess access = {kTaggedBase, JSObject::kPropertiesOffset,
                         MaybeHandle<Name>(), Type::Internal(), kMachAnyTagged};